Automatic electric switch



April 20, 1948. R. E. SWISHER ET AL I AUTOMATIC ELECTRIC SWITCH Filed Jan. 17, 1946 Wm M mm r9 M11 I M .s m r J my 3 m N W Q an 8 Em -m H MG d m Patented Apr. 20, 1948 UNITED STATES PATENT OFFICE 2,440,028 AUTOMATIC ELECTRIC SWITCH Robert E. Swisher and George W. Gates, Kansas City, M

Application January 17, 1946, Serial No. 641,704 7 Claims. (Cl. 172-126) Our invention relates to mercury switches and means for controlling the same. One object of the invention is to provide a new and useful mercury switch whereby one or more electrical circuits may be opened or closed with a minimum of sparking at the terminals thereof.

A further object is to provide a mercury switch including a pair of oscillatory tubes arranged side by side and having their longitudinal axes extending at intersecting angles to approximately resemble the numeral 8 disposed in approximately a horizontal plane instead of, as normally, in a vertical plane. The tubes have communicating ends so that a circuit-closing mass or globule of mercury may run in cycles through the tubes by force of gravity during oscillation of the tubes and close one or more circuits, as will hereinafter more fully appear.

Another object is to provide each tube near one end with a pair of spaced terminals which are sealed in the tube and have their inner ends disposed in the path of the globule. The outer ends of one pair of terminals are connected to a normally open circuit including means adapted to cooperate with spring-means in controlling the oscillatory movements of the tubes. The other pair of terminals are connected to a shunt circuit which is connected across the normally open circuit. A second shunt circuit is also connected across the normally open circuit and like the first shunt circuit, cooperates with the normally open circuit in controlling the operation of the oscillatory switch. The tubes are also provided intermediate their ends with one or more pairs of spaced terminals arranged in the path of the globule for the purpose of closing other circuits having electrical instrumentalities for performing various duties, such, for instance, as operating clock-chimes and the like.

Other objects will hereinafter appear and in order that the invention may be fully understood, reference will now be had to the accompanying drawing in which:

Fig. 1 is a side elevation of the mercury switch in normal position, and electrical circuits associated therewith for cooperating with the switch in the operation thereof.

Fig. 2 is a top plan view of the switch with the circuits removed.

Fig. 3 is a cross section of the switch tubes on line 3 of Fig. 1.

Referring in detail to the different parts, 2 designates the mercury switch which includes a pair of tubes 4 and 6, from which the atmosphere has been exhausted and which communicate with each other through semi-circular left and right ends 8 and 10, respectively. The tubes 4 and 6 are slightly inclined in opposite directions to each other as disclosed by Fig. 1, and may consist of glass, plastic or other suitable nonconductive material. The switch 2 is operably mounted for oscillation across a horizontal plane, on a transverse axis so that when in operation it is alternately inclined in opposite directions. The transverse axis may comprise trunnions l2, the adjacent ends of which are connected to the switch in any appropriate manner, such for example, as by a band I4 embracing the tubes 4 and 6. The distal ends of the trunnions l2 are operably mounted in the bifurcated upper end l5 of a supporting member l6 fixed at its lower portion to a base plate IS. A globule of mercury 20 is disposed Within the switch 2 and forms a component part thereof. In the present instance it is adapted to first run by gravity through the tube 4 and back to the starting point through the tube 6, as will hereinafter more fully appear. The left hand end of the tube 4 has two spaced terminals 22 and 24 sealed therein, and the tube 6 has a like pair of spaced terminals 26 and 28, respectively, sealed in its right hand end. The foregoing terminals are also arranged in the path of the globule 20 to be contacted thereby as it runs through the tubes to close circuits which assist in oscillating the tubes.

The terminals 22 and 24 are connected to a normally open local circuit which is connected to positive and negative mains A and B, respectively. The local circuit proceeds as follows: A wire 30 leading from the main A to a switch 32, wire 34, terminal 22, globule 20, terminal 24, wire 36, solenoid 38, wire 40, armature 42 of a relay 44, contact 46 normally engaged by the armature 42, and a wire 48 leading from the contact 46 to the main B, thus completing the local circuit.

When the switch 32, which may be of any appropriate type, shown in the present instance as a push-button, is closed the normally open circuit above described becomes energized by current from the main A and in turn energizes the noid 38, causing it to pull the tubes 2 and 3 by means of the armature 50 and a connecting rod 52 connected at its upper forked end by pivots l'2a to opposite sides of a reinforcing band 54 embracing the switch 2 near the right end thereof. As the armature 50 moves downward it swings the switch 2 clockwise until inclined downwardly towards its right end as indicated by the dotted line a, Fig. 1. The globule 26 which has been in simultaneous engagement with the terminals 22 and 24, now runs by gravity to a wire 62 leading from the contact 60 to the juncr 7 tion 51.

When the globule 2B contactsethe.t'erminalsgzli the solenoid 38. However, when said 58, which is forced and 28, as above stated, deenergization oithe sole.- l

noid 38 is efiected through the action of a second shunt irc it nnected aq qssthe no ll pe cuit nd in udin them nl el w h T cond hunt ci cui li ii ceeble: e PW Avire 543 onnected'to the wirefiiiinadvanceof the wire 55, terminal 26:, a the globule 20; the terminal -28, wire 66, the relayed; and wire-68 leadingfrom the re a to ,thewir fii ec 9 .et h the 4' energizes the latter, causing it to draw aiure wev ro l 'e o ct 4 a his interr t h u r nt owin h o g t solenoid 3B, Theswitch] is: then swung counter l ckw se. by "a coil p in 70, until he e t e oithe, tube... i. and. Bare again inclined downird t9 rm@ .-P9 ti e 'zthe Swit 2 i swun toner: ckwise he if l l x i w ich has und w i n o th can a d, o by. gravity. through i the latter ......ten rn n lt and a ain. m aneoi s v n ee is th term n l 22 n ,,.2.i re nectivelv, "w ee he leb' l uns rom. .t er ain -1 5 1n ..?.3;. theshun and the e axarma re mo s int n eie men wi h p onie '4 i .Theie i i lg lit Wh un r, te ant i c hnegtedati i .91 51 v j and 'i L'fiXe d to he baseplate l8 andth'e left end of ih ii iei resnet vl v .,.I. ,a d. tion' to h c m rials. above de lcnbe thetubese and re pxgvi fl in ermed a e the ends manual f terminals; ,5 and. 1. .8 an fie euand iiiigfitan .32, andQA and. 95, respectively, eachphillq'i Whichlif, si ult ane.ollsly,but moment r 'e i edbv. t e... elbbllle. it as, it. ru s. by avit u h thetu ejs iandffi E chpair of the intermediate terminals may b9 iconnected to a-.circuit,.fnot 'shawuwmeh iriayjincludevarious iristrumentaliti'es Lion perrorming, useful work,

Fromthe foregoing. description it 'is apparent that we navep'r. videdan electric t'ch and circuits for controll ng the-same whichfare economical in use of-electricalcurrenta jeiso'mat wehave trolling alarge, number .ormmuus am; thatthe operation of theswitch is attended with but little friction. 1

provided a switch which may be. utilized for con- "'1'... 13; 1 i 5;. 1 x t is also to' be understood that insulation is 1 usedwhereverneeded on the switch and in the r u ts v. t L r Having thus described our. invention what we laim anddesire measu -hr L tters Reie tisl :1...- n a mercur switch watubes. communicatin 13217 131 1 r ctive nd nd'ha i g the rlo e udin lax s ra ed." a op s te nc t on to: each: other, a suitably W supported transverse axison which.

tion of the tubes involving a normally open electrical circuit, a first pair of terminals sealed in one end. of one tube and connected in series with said circuit, a second pair of terminals sealed in the opposite end of the companion tube, a circuit-completing globule of mercury adapted to describe an orbit through the tubes during the oscillation thereof and contact each pair of terminals, electrical means energized by the normally open circuit, adapted to swing the tubes downward in one direction, means for deenergizing said electrical means and arranged in series with the second pair of terminals, and means for swinging the tubes downward in the opposite diq l r .l

' 2. ;;1- a mercury switch, two tubes comand mounted for simul- V a pair of spaced terminals sealed inpne end of one tube, a circuit-closing globule of mercury normally in contact with the terminals and adapted to run in a cycle through the tubes when ,thelatterare oscillated a normally I, open electrical circuit in series with the terminals, a, manual switchior, cooperating with the globuleand the terminals in closing the circuit, asolenoid in serieswith the circuit, a plunger controlled by thesolfenoid andadapted toswing the tubesdownwardat one en -and t r cause the. globule town by gravity, fromthe terminal into the. opposite. .endoi :the. companion tube, a normally open shunt circuit connected across the first-mentioned circuit and adapted to be closed by the. plunger as the latter swings. the tubes downward :as ,stated, said shunt, circuit, when closed, being adapted, to energize the solenoid when theglobuleruns from the-terminals means for deeriergizing.theLshuntcircuitWhen the glob by the" solenoid and adapted to swing the, tubes downward at one ,end and thereby cause the globule to run by: gravity from the terminalsinto the opposite. end of the companion tube, a, shunt circuit connected across the first-mentioned circuit, normally, open; contacts in thefshunt jcircuit adapted to be closed by theplunger ,when swinging the tubes downward atone end, said shunt circuit, when closed, being adapted to energize the solenoid when the globule runs by gravity from the terminals, means for' deen'ergizing. .the shuntcircuitwhen the globule entersthe opposite end of the companion tube, an'dmeans for swinging the tubes back to first. position,

l. In a mercury switch, two tubes communicatingat e'ache'nd and mounted ior'simultaneous oscillation, a pair of spaced terminals sealed in one end of one tube, a 'circu'it closing' globule of mercury normally in contact with thefterminals and adapted to run in acycle through the tubes when the latter areoscillated, a normal jop en ui t in, series with the terr ls, a

in series with the circuit, a plunger controlled by the solenoid and adapted to swing the tubes downward at one end and thereby cause the globule to run by gravity from the terminals into the opposite end of the companion tube, a shunt circuit connected across the first-mentioned circuit, a relay in series with the last mentioned circuit, normally closed contacts in series with the firstmentioned circuit and adapted to be opened by the relay and thereby eiTect deenergization of the solenoid, means the shunt cirtube, and resilient means for swinging the tubes back to first position.

5. In a mercury switch, two tubes communicating at their ends with each other and having described an orbit through the tubes during oscillation thereof and successively contact the first and second pairs of terminals, means for normally holding the first-mentioned end of the tubes lower than the distal end, thereby normally retaining the globule in engagement with the first normally open circuit in series with the first pair of terminals, a solenoid in by the solenoid and adapted to continue to energize the latter on interruption of the circuit.

6. In a mercury switch, two tubes communicating at their ends with each other and having their longitudinal axes arranged at opposite inclinations to each other, supporting means on oscillate, a first lation thereof and successively contact the first and second pairs of terminals, means for normally holding the first-mentioned end of the tubes lower than the distal end, thereby normally retaining the globule in engagement with the first pair of terminals, a normally open circuit in series with the first pair of terminals, a solenoid in series with said circuit, adapted to be energized and draw down the raised end of the tubes when the circuit is closed, thereby causing the globule to run down into contact with the second pair of terminals and thus open the circuit, electrical led by the solenoid and adapted energize the latter on interruption of the circuit, and means for deenergizing the solenoid.

7. In a mercury switch, two tubes communicating at their ends with each other and having their longitudinal axes arranged at opposite intube, a second pair or" contacts sealed in the distal end of the other tube, a globule adapted to describe an orbit through the tubes during oscillation thereof and successively contact the first and second pairs of terminals, means for normally holding the first-mentioned end of the tubes lower than the distal end, thereby normally retaining the globule in engagement with the first pair of terminals, a normally open circuit in series with the first pair of terminals, a solenoid REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 789,336 Paulsen May 9, 1905 822,325 Tornberg June 5, 1906 1,083,580 Zenke Jan. 6, 1914 1,537,796 Bossard May 12, 1925 2,156,684 Fisher May 2, 1939 

